Hauling device for ski lifts



' April 22, 1969 r u. CARLEVARO 7 3,439,627

HAULING DEVICE FOR- SKI LIFTS Filed Feb. 20, 1967 INVENTOR ATTORNEYS United States Patent HAULING DEVICE FOR SKI LIFTS Ugo Carlevaro, 43 Via San Secondo, Turin, Piedmont, Italy Filed Feb. 20, 1967, Ser. No. 617,300 Claims priority, application Italy, Mar. 26, 1966, 32,808/66 Int. Cl. B61b 11/00, 7/04, 7/10 U.S. Cl. 104-173 7 Claims ABSTRACT OF THE DISCLOSURE It is well known that, in ski lifts, there is provided a plurality of individual hauling means for any single or several skiers, all said means being connected to the continuous carrying cable of the lift; in more improved lifts, the connection of said means, which are emboided by individual towing ropes, is realized through interposed hauling devices, wherein an individual rope is wound on a winch fitted with a rewinding spring, said hauling devices releasing, at the moment in which a skier grasps the individual towing rope, a certain length 'of individual rope before exerting a positive traction on the skier, whilst at the moment wherein the skier releases the individual towing rope, they rewind again said individual rope.

The most improved devices comprise means for braking the rotation of the winding drum of the individual rope, in order to attenuate the sudden jerks occurring at the end of the Winding up and at the end of the unwinding stages. These means are however only partially useful in said known braking devices, or are embodied by rather complicated constructional features which are easily liable to breakdowns.

It is therefore the purpose of this invention to provide a hauling device for ski lifts working merely in a mechanical Way, simply and sturdily built, subject only to a very slight extent to breakdowns, even under the most dificult working conditions of said devices, and in spite of that, able to maintain a damped braking action during the rewinding period and a much more powerful and substantially progressive braking action during the unwinding of the towing rope, in order to set going the skier without jerks, and to avoid the end stroke tightening of the rewinding spring, whereby breakdowns easily may occur.

The inventive idea of this invention consists in applying, around the axle of the rewinding winch of the individual towing rope, a braking member on which acts a mechanical brake, such as for example a band brake, said brake being a weakly acting unwinding brake during the rewinding of the rope and a strongly acting rewinding brake during the unwinding of the rope; furthermore, the invention provides means capable of gradually increasing the load on said mechanical brake as the unwinding of said rope takes place, and vice versa as the rewinding of the rope proceeds.

A preferred, but only illustrative and not limitative embodiment of the hauling device according to the invention is shown in the accompanying drawings, in which:

FIG. 1 is a diametrical section of the device;

FIG. 2 is a plan view in axial direction of said device,

3,439,627 Patented Apr. 22, 1969 wherefrom the cover with the rewinding spring and the brake drum have been removed; and

FIG. 3 shows diagrammatically the application of the device.

The hauling device shown in the drawings comprises a box 1, said box being connected by means of a suspension 19 (FIG. 3), to the continuous carrying cable 20 of the lift, and containspivoted on the shaft 2 (FIG. 3) the winding drum 3 for the individual towing rope shown at 21 in FIG. 3, as well as the rewinding spring 4 comprised as usually of a flat spiral spring, whose ends are secured the first to the shaft 2 and the second to the closing cover 5 of the box 1. The above said parts as well as the remaining parts of the hauling device not mentioned in the present description are substantially known.

According to the invention, on the shaft 2 of the winding drum 3, there is wound a brake band 7, secured at 8 to a wall 9 integral with the box 1, and loaded at 10 by a compression spring 11 whose tension may be adjusted by means of a threaded nut 12, said nut being accessible from the outside by unscrewing a threaded cap 13 that closes normally a corresponding hole in the box 1. The winding direction of the rewinding spring 4 is selected in such way that the hand brake now described acts as a winding brake when the device rotates in the unwinding direction of the individual towing rope, and acts as an unwinding brake when the device under action of the rewinding spring 4, rotates in the rewinding direction of the individual rope.

In such conditions, it is obvious that during the rewinding of the individual towing rope, a moderate brake action is performed which may be adjusted in order to attenuate the end stroke jerk, without reducing however too much the rewinding speed; on the other hand, the braking action during the unwinding of the individual towing rope will be substantially stronger, for example ten times more, and this precisely during the starting period of the towed skier.

The invention provides however an easily built means in order to enjoy the advantageous features of the device just described and to make progressive its braking action, although said action is already differentiated according to the direction of rotation.

According to said further feature of this invention, the nut 12 of the compression spring 11 loading at 10 the brake band 7, is supported by a rod 14 articulated with a lever 15 which is pivoted at 16 on the wall 9, said lever being provided with a rotatable roller 17 acting as a tappet for a cam 18, said cam being formed by a cam shaped block screwed on a threaded portion 2a of the shaft 2 and being prevented from rotating by polygonal coupling means with a fixed part; in the example shown, the block 18 has a rectangular section and slides in a corresponding rectangular aperture 9a in the wall 9. The shape of the block 18 and the thread hand of the threaded portion 2a are selected in such a manner, that the displacement of the lever 15 due to the roller 17 sliding on the cam 18, will cause a load increase on the compression spring 11, progressively with the unwinding of the individual towing rope from the drum 3*. By suitably choosing the shape of the cam 18, it is therefore possible, to increase the braking action during the unwinding of the individual towing rope according to a desired law, and particularly it can be positively obtained that the unwinding will be stopped after the skier has started but before the turns of the rewinding spring 4 have been tightened the one against the other, with breakage danger. The start of the skier is thereby carried out in the most comfortable and least dangerous manner.

As it can be seen, the device according to the invention comprises no delicate part unduly subject to breakages, to wear or to other deterioration. Furthermore, the device being merely a mechanical one, hence without hydraulic or similar means, it is not influenced by temperature changes, oil leakages or other fortuitous events.

The mechanical brake described in band form, may also be a shoe brake, a disk brake or any other suitably built brake.

Furthermore, if the opportunity should arise, the braking device above described may be integrated with a centrifugal brake of well known type, particularly with the purpose of controlling the rewinding speed.

Having thus described my invention, what I claim is:

1. A hauling device for connecting the individual towing rope for skier to the carrying cable of a ski lift, said device comprising a box, a suspension means for connecting said box to the continuous carrying cable, a shaft pivoted in said box, a winding drum keyed on said shaft for receiving the wound individual towing rope, a rewinding spring connected to said shaft and to said box for rotating said shaft and said rewinding drum and for winding up said individual towing rope on said winding drum, a brake drum fixed to said shaft, a brake band cooperating with said brake drum, means for connecting positively a first end of said brake band to said box and a connection spring for connecting resiliently a second end of said brake band with said box, whereby, when said rewinding spring rotates said shaft, rewinding drum and brake drum so as to rewind the individual towing rope, said brake band exerts but a slight braking action, whereas, when said individual towing rope is unwound from said rewinding drum, thereby rotating said rewinding drum, shaft and brake drum against the action of said rewinding spring, said brake band exerts a powerful braking action.

2. A hauling device as set forth in claim 1, wherein said connection spring is a compression spring, and further comprising a threaded rod passing axially through said connection spring, a nut screwed on said threaded rod and abutting an end of said spring, said box having an aperture through which to adjust said nut and a cap for closing said aperture.

3. A hauling device as set forth in claim 1, further comprising an adjusting device connected to said shaft in order to be actuated by the rotation of said shaft, and also connected to said brake band in order to adjust its 4 action, whereby the braking effect varies during the rotation of said shaft.

4. A hauling device for connecting the individual towing rope for a skier to the continuous carrying cable of a ski lift, said device comprising a box, a suspension means for connecting said box to the continuous carrying cable, a shaft pivoted in said box, said shaft having a threaded portion, a winding drum fixed on said shaft for winding the individual towing rope, a rewinding spring connected to said shaft and to said box for rotating said shaft and said rewinding drum and for winding up said individual towing rope on said winding drum, a brake drum fixed to said shaft, a brake band cooperating with said brake drum, a lever connected to said box, a connection spring for connecting resiliently said brake band to said lever, a block screwed on said threaded portion of said shaft, said block having a cam-shaped edge, and a tappet member mounted on said lever and abutting upon said cam-shaped edge.

5. A hauling device as set forth in claim 4, wherein said tappet member is a roller rotating on said lever.

6. A hauling device as set forth in claim 4, wherein said screwed block passes through an opening in a portion of the box, whereby said block is prevented from rotating.

7. A hauling device as set forth in claim 4, wherein said edge of said screwed block is shaped for stopping the rewinding drum before the rewinding spring has been completely tightened on itself.

References Cited UNITED STATES PATENTS 2,677,331 5/1954 Hauseman 104173 3,358,612 12/1967 Bleuer l04-173 FOREIGN PATENTS 1,109,556 l/1956 France.

62,599 6/ 1940 Norway.

292,280 10/ 1953 Switzerland.

ARTHUR L. LA POINT, Primary Examiner.

D. F. WORTH III, Assistant Examiner.

U.S. Cl. X.R. 104178 

